A mixture of light, consisting of wavelength 590 nm and an unknown wavelength, illuminates Young's double-slit and gives rise to two overlapping interference patterns on the screen. The central maximum of both lights coincide. Further, it is observed that the third bright fringe of known light concides with the 4th bright fringe of the unknown light. from this data, the wavelength of the unknown light is

A mixture of light, consisting of wavelength 590 nm and an unknown wav

1.	A mixture of light, consisting of wavelength 590 nm and an unknown wavelength, illuminates Young's double-slit and gives rise to two overlapping interference patterns on the screen. The central maximum of both lights coincide. Further, it is observed that the third bright fringe of known light concides with the 4th bright fringe of the unknown light. from this data, the wavelength of the unknown light is
Answer» 885.0 nm 443.5 nm 776.8 nm 393.4 nm Solution :As 3 fringe widths of wavelength `LAMDA=590nm`, coincide with 4 fringe widths UNKNOWN wavelength `lamda.`. Hence `3beta=4beta.` and it LEADS `3lamda=4lamda.`. `THEREFORE lamda.=(3)/(4)lamda=(3)/(4)xx590nm=442.5nm`.

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